Metronome
by AllusionToAnIllusion
Summary: It's the little things that become the rhythm of their life together.


_For Bee, the capital of my heart._

* * *

She wakes in darkness, moonlight caressing the walls and draping shadows over the rumpled sheets. A quick glance at the clock tells her it's almost 3:00 am and for a moment she has no idea why she's up this early when she doesn't have to be. Then her senses expand beyond her sleep-muddled haze and she hears it, soft and almost unnoticeable against the backdrop of sirens and alarms.

She turns and rests her head against her forearm as she watches him, lips pursed in concentration as he types. Sometimes it catches her off guard, how amazing he is at what he does, how simple movements of his hands create stories she gets lost in. He hasn't noticed she's awake yet, too focused and, well, inspired it seems. She doesn't even try to hide the unbidden smile at the thought, limbs still a bit sore from their third round of _inspiration_.

She looks up at him again, eyes tracing the line of his bicep down to his knuckles and _wait_ –

His fingers are moving too slowly, a lazy pace that doesn't at all match the trapped story in his eyes. _Oh, Castle._

"You know you don't have to do that." She laughs when he startles, fingers jerking in surprise as his whole body jumps. He turns to look at her, surprised eyes turning tender at the sight of her in his bed. She knows that sometimes he can't quite wrap his mind around it, can't believe she's here with him after all the years and all the waiting. It breaks her heart.

"Staring at my manly features?" She snorts into the pillow – _her pillow_ – and beams at him completely against her will.

"Mmm, I get my fill at the 12th. Your ass isn't _that_ great." He presses one last key, saving his work a reflex by now, before he's on top of her. She loves how he surrounds her, how his body and his words wrap around her.

"Checking me out at work, huh?" He leans down, nips at her jaw and she almost doesn't manage to answer him through the gasp.

"I deserve some – ah – some eye candy now and then. Besides, you bend over a lot." His growl vibrates into her cheek, permeates her skin and settles in her bones. His hands are everywhere at once but not at all where she wants them and _oh _screw her sore limbs, she's so ready for round four – but then his mouth is gone and all she's left with is a cold, wet spot on her neck.

"Wait, did my typing wake you up?" She huffs and looks up at him, entirely too far away for her liking. She arches up, wraps her arms around his chest and tugs but he resists her. "Kate."

"Castle, you don't have to try to type softly for me." She gives up on bringing him back, leaves her hands there to stroke at the strong muscles of his back.

"But I know you don't like it. I can write in the study if you want so I don't wake you up." She goes to him then, kisses him tight and quick because he's so sweet but so stupid sometimes. When she drops back down, he finally follows.

"So that's a yes to the study, then?"

"That's a _stop being so stubborn_. I like it when you write in bed. Don't you dare stop." His eyes are so boyish, so hopeful, but they're still clouded with disbelief. She wants the untainted blue back.

"But you said–"

"I know what I said. I changed my mind. It's nice, the rhythm of it. I know that you're there." It takes a moment but then he's beaming at her, lighting up his eyes and showing off those laugh lines she loves to trace. She laughs when he rolls them over, pulling her on top of him. His heartbeat is right under her ear and even when he tries to pull her up to his face, she doesn't go.

She likes it here, likes the steady thump under her cheek as she nestles into him. She knows that when she wakes up she'll be sweaty and gross and the heat from his body will be too much, but she doesn't want to go to sleep without the constant beat of his heart.

* * *

Steams swirls up into his face, skirting his lashes as he breathes in the heavenly scent of coffee, a savior after a night with next to no sleep. He picks up the mugs, warm to the touch, and makes his way back to her desk. It's harder than usual to stay away from her today, so much so that she had to send him to the break room under the guise of needing more coffee just so he'd stop touching her.

He stops in the doorway, watches the way her hair bounces as she shakes her head exasperatedly at Ryan and Esposito. He just wants to run his fingers through it, curl his palm at her nape and pull her into him – he can't help it after what she said last night, or, well, early this morning actually. It means much more than it should, he knows that. But his heart still clenches when he remembers the words she whispered into his lips.

Johnson pushes past him on his way into the break room and the haze breaks. Clearing his throat of leftover emotion, he forces the adoration from his eyes and calmly walks to her desk. But when he gets there, nobody notices him. It seems he's interrupted something.

"Seriously, how'd you guys get together? Castle send you one too many bouquets?" He smirks because, oh, this could not be better.

"Actually, she showed up at my door and kissed me." He can't see her face, but from the way the boys are looking at her and how her body suddenly goes rigid he can tell she's blushing.

"Why, Beckett, we didn't figure you for a romantic."

"Bro, have you seen the way these two have been looking at each other lately? You know, you guys should probably tone it down if you don't want Gates to know."

"Oh, like it's any different from before they got together."

"Hey, guys, _case_." She sounds like she's ready to explode. It's hilarious. She stands up, pointedly not looking at him, and makes her way over to the murder board. He throws the boys one last smirk before following her. He hangs back and rests against a desk, watches her focus the exasperation on the case and, thankfully, not on him. From that first case with her, he's always admired the way she can channel her emotions, how she takes that energy and uses it to her advantage. It was the first of her traits he ever gave to Nikki.

She's pacing, heels _clack clack clacking_ against the hardwood floor of the bullpen. He hears the frustration, both with the case and with all three of her boys, in her walk. He reaches out, wants to snag her waist before he remembers he can't. Instead, he clears his throat and pats the spot next to him when she turns around.

"You know why I love your heels?" She sits with him on the desk, all grace and long legs and a fire in her eyes. She raises an eyebrow when he doesn't continue, trying for indifference but he sees the curiosity in her expression.

"I can tell it's you from the sound of them on the floor. The rhythm of your walk, sure and unique – it's all you." The defiance, the coolness – everything melts into a shy grin.

"I can tell when it's you too, Castle." She cocks her head to the side, looks up at him from under her lashes with this absolutely undoing mix of girlishness and adoration.

"Really?" She nods, hair falling into her face before she brushes it behind her ear. He thinks she might giggle, but then she starts speaking again.

"It's hard to mistake your stomping for anything else." He pouts, an affronted scoff making its way past his tongue as she saunters back over to where he left her coffee.

* * *

She stretches out her legs, sighs as her muscles relax and she sinks into his sinfully comfortable couch. She feels the flex of his thigh under her head, the play of muscle as he gets comfortable. The loft is quiet except for their combined breathing as he proofreads his latest chapters and she reads her book.

She tries to concentrate on the pages in front of her, but his thigh clenches whenever he finds something to fix and it's utterly distracting. She can just picture the way his eyes scan the page, how his lips move but no sound comes out, the flex of his fingers over the keys – the image fills her up. She stops trying to read that one sentence for the seventh time, and chooses to listen to his breathing in the silence.

She's never been very good at being still, at the hush of calmness. But it's easier to appreciate the quiet moments with him. Maybe because she wanted them for so long, she didn't just dream of passion and fire for all those years. She reaches back, suddenly so overwhelmingly grateful for him, for _them._ Her fingers stroke the hair on his arm and even though he doesn't seem to notice, this is all she needs.

She inhales deeply, content with the peaceful ease of the night, and notices that their breathing has synced. She exhales then, and he does the same. And in the quiet, everything is clear. She finds her words in the cadence of their breath. And with that same tranquil rhythm, she sets them free.

"I love you."


End file.
